He also helped to orchestrate the “green jobs” strategy under the Obama administration’s economic stimulus package.
He supported landmark regulations on coal plants and automobile tailpipe emissions as vice president, and helped to secure the Paris Agreement, the 2015 pact to limit the rise of global temperatures .
His climate change plan would spend $1.7 trillion over a decade, impose a tax on greenhouse gases and aim to bring carbon emissions to net zero by 2050.
Yet Ms. Mankel, a full-time volunteer for the youth-led Sunrise Movement, was disappointed.
And so it has gone for Mr. Biden, whose experience in the wars over c limate change is unmatched among Democratic contenders for the White House, but whose image remains soporific to the young activists driving the debate.